The invention pertains to a transport device for substrates to be coated in a vacuum coating system with a substrate carrier plate removably attached to a support element of a base, the carrier plate being designed to hold at least one substrate.
Transport devices of the type described above are currently used in cathodic sputtering systems to transport the substrates to be coated to the individual treatment stations of the system and to hold them there during processing. Because the transport devices in a cathodic sputtering system are subjected to high temperatures, because a high vacuum prevails in such systems, and because no contaminants may be allowed to the enter the system with the transport devices, these devices must meet very stringent requirements. The transport devices may not have any parts which cannot withstand the high temperatures in the system or which could carry along gases which would then be released in the system and interfere with the coating process. It is also very important that the transport devices not have any moving parts which could produce abrasion, because the generation of particles thus induced would make it impossible in most cases to obtain a good coating. Because the transport devices with the substrates must be transferred into the various chambers of the coatings system through locks, they should be as narrow as possible so that the cross section of the locks can be kept small.
Up to now, the transport devices have been designed in such a way that a substrate carrier plate could be attached to each of the two sides by hand. If it is desired to accomplish the loading process automatically by means of a robot, however, the substrate carrier plates must be pivoted from a horizontal position, in which they are loaded with the substrates, into a vertical position and then moved transversely to their long direction toward the support elements and fastened to the support elements. The motions required for this process should be as simple as possible. The transport device may not be provided with any devices for the docking with the support elements which do not meet the requirements described above, i.e., which cannot withstand high temperatures, which could bring air into treatment chambers under high vacuum, or which could produce abrasion during clamping motions and thus introduce contaminants into the system.